NEW BRUNSWICK, N.J. (CBSNewYork/AP) — A Chinese-born chemist who worked for a decade for Bristol-Myers Squibb was sentenced to life in prison in New Jersey Monday, after being convicted of poisoning her husband rather than letting him divorce her.

Tianle Li won’t be eligible for parole for more than 62 years for the killing of Xiaoye Wang, a computer software engineer, in early 2011. The 42-year-old Li was convicted in July of murder and hindering apprehension. Her attorney had sought a 30-year sentence.

“This was planned, calculated and committed in a cruel and depraved manner,” New Jersey State Superior Court Judge Michael Toto said in pronouncing the sentence.

Li has continued to deny any role in her husband’s death, said her attorney, Steven Altman. In a brief, tear-filled statement read in court Monday, Li said she prays for her husband’s soul and will appeal the trial verdict.

The couple had a son who is now 4 years old and in the care of relatives.

Thallium has been banned for consumer use in the U.S. since 1972. It can be fatal in doses as small as a gram and has been called “the perfect poison” because it is difficult to detect in lab tests. It was initially suspected to be the toxin used in the 2006 fatal poisoning in London of former Russian KGB agent Alexander Litvinenko, but it was later determined he had ingested the rare radioactive isotope polonium-210.

“Sometime the window is open. You hear the fighting and the wife’s voice was louder than the husband’s voice,” Prakash Patel told CBS 2 at the time.

Investigators said Li initially lied to them soon after her arrest, but neighbors wondered, given all the times police came to the home, how she expected to ever get away with it.

“You would think that doing something pre-planned like this and something where they can find out and connect the dots, I don’t know that it was really well thought out for her to do something like that. She had an opportunity to leave,” Hisham Zahran said in 2011.

At the sentencing hearing Monday, Altman countered that Li was at her husband’s side in the hospital, even changing his bedpan. But prosecutors said this too was a calculated ruse.

“She was secretly keeping a journal of all his symptoms, wondering when he was going to die,” prosecutor Christie Bevacqua told Toto. “She calculated every aspect of her husband’s murder; not only how to do it, but how to get away with it. She thought she was going to get away with this murder.

“She chose to murder her husband rather than allow him to divorce her.”

Li, who is from Beijing, came to the U.S. in the late 1990s and worked for Bristol-Myers Squibb for about 10 years. She met Wang when both were studying at the University of Pennsylvania. The couple lived in Monroe, in central New Jersey, and prosecutors said at the time of Li’s arrest in February 2011 that police had been called to the residence several times for domestic disturbances.

Altman said in court Monday that some of the disputes arose from culture clashes between the Americanized Li and her husband’s more traditional family, who had come to help the couple care for their son.